Q/BQB 310-2023 Continuously hot-rolled steel sheet and strip for automobile structural use
1 Scope
This document specifies the dimension, shape, technical requirements, inspection and testing, as well as packaging, marking and inspection documents of continuously hot-rolled steel sheet and strip for automobile structural use.
This document is applicable to the continuously hot-rolled steel strip made of carbon and microalloyed steel with good cold-forming performance as well as the steel sheet cut horizontally and the slit wide strip cut vertically therefrom, hereinafter referred to as steel sheet and steel strip, produced by Baoshan Iron & Steel Co., Ltd. The products are used to manufacture automobile frames, crossbeams, vehicle wheels, automobile transmission shaft tubes, automobile axle housings and other structures.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 222-2006 Permissible tolerances for chemical composition of steel products
GB/T 223 Methods for chemical analysis of iron, steel and alloy (Applicable parts)
GB/T 228.1-2021 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 232 Metallic materials - Bend test
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 4336 Carbon, medium- and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (Routine method)
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 13298 Inspection methods of microstructure for metals
GB/T 13299-1991 Steel - Determination of microstructure
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (Routine method)
GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method
Q/BQB 300 General rules of package, mark and inspection documents for continuously hot-rolled steel sheet and strip
Q/BQB 301 Dimension, shape, weight and tolerance for continuously hot-rolled steel sheet and strip
3 Terms and definitions
No terms and definitions are listed in this document.
4 Classifications and codes
4.1 The designation, nominal thickness and purpose of steel sheet and strip are shown in Table 1.
4.2 By surface treatment method:
a) acid pickled surface;
b) rolled surface.
4.3 By surface quality classes:
a) ordinary surface (FA);
b) superior surface (FB);
4.4 By product category:
a) hot-rolled steel strip;
b) hot-rolled steel sheet;
c) hot-rolled flat steel strip;
d) hot-rolled slit wide steel strip;
e) hot-rolled pickled steel strip;
f) hot-rolled pickled steel sheet.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classifications and codes
5 Information needed in ordering
6 Dimension, shape, weight and tolerance
7 Technical requirements
8 Inspection and testing
9 Packaging, marking and inspection documents
10 Rules of rounding off for numerical values
11 Annex
Annex A (Informative) Comparison between similar designations in this document and relevant standards
